By powders for the ice cream cubes, I meant nonfat dry milk powder.
Extra container at Costco. I have seen at the Vitamix traveling road show at Costco (happens about every 2 months), I have seen low profile 48 oz wet container available individually and the 32 oz dry grains container individually. ("Wet" container is standard type, it pulls the ingredients down into the blade for blending, a "Dry" container has a blade that tosses the ingredient upwards for grain grinding) At those times prices were slightly better than vitamix directly. You can buy all the containers separately right from vitamix. One time an internet search lead me to QVC and they had an individual container for $50 compared to $99-129. I like the 32oz wet container for 1 person size smoothies - only above 8oz minimum for good blending.